1 /*
2  * Copyright (C) 2016 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 package com.android.contacts.model.account;
17 
18 import android.app.Activity;
19 import android.app.Fragment;
20 import android.app.LoaderManager;
21 import android.content.Context;
22 import android.content.IntentFilter;
23 import android.content.Loader;
24 import android.os.Bundle;
25 
26 import com.android.contacts.model.AccountTypeManager;
27 import com.android.contacts.util.concurrent.ListenableFutureLoader;
28 import com.google.common.base.Objects;
29 import com.google.common.base.Predicate;
30 import com.google.common.base.Predicates;
31 import com.google.common.util.concurrent.ListenableFuture;
32 
33 import java.util.List;
34 
35 /**
36  * Loads the accounts from AccountTypeManager
37  */
38 public class AccountsLoader extends ListenableFutureLoader<List<AccountInfo>> {
39     private final AccountTypeManager mAccountTypeManager;
40     private final Predicate<AccountInfo> mFilter;
41 
AccountsLoader(Context context)42     public AccountsLoader(Context context) {
43         this(context, Predicates.<AccountInfo>alwaysTrue());
44     }
45 
AccountsLoader(Context context, Predicate<AccountInfo> filter)46     public AccountsLoader(Context context, Predicate<AccountInfo> filter) {
47         super(context, new IntentFilter(AccountTypeManager.BROADCAST_ACCOUNTS_CHANGED));
48         mAccountTypeManager = AccountTypeManager.getInstance(context);
49         mFilter = filter;
50     }
51 
52     @Override
loadData()53     protected ListenableFuture<List<AccountInfo>> loadData() {
54         return mAccountTypeManager.filterAccountsAsync(mFilter);
55     }
56 
57     @Override
isSameData(List<AccountInfo> previous, List<AccountInfo> next)58     protected boolean isSameData(List<AccountInfo> previous, List<AccountInfo> next) {
59         return Objects.equal(AccountInfo.extractAccounts(previous),
60                 AccountInfo.extractAccounts(next));
61     }
62 
63 
64     public interface AccountsListener {
onAccountsLoaded(List<AccountInfo> accounts)65         void onAccountsLoaded(List<AccountInfo> accounts);
66     }
67 
68     /**
69      * Loads the accounts into the target fragment using {@link LoaderManager}
70      *
71      * <p>This is a convenience method to reduce the
72      * boilerplate needed when implementing {@link android.app.LoaderManager.LoaderCallbacks}
73      * in the simple case that the fragment wants to just load the accounts directly</p>
74      * <p>Note that changing the filter between invocations in the same component will not work
75      * properly because the loader is cached.</p>
76      */
loadAccounts( final FragmentType fragment, int loaderId, final Predicate<AccountInfo> filter)77     public static <FragmentType extends Fragment & AccountsListener> void loadAccounts(
78             final FragmentType fragment, int loaderId, final Predicate<AccountInfo> filter) {
79         loadAccounts(
80                 fragment.getActivity(), fragment.getLoaderManager(), loaderId, filter, fragment);
81     }
82 
83     /**
84      * Same as {@link #loadAccounts(Fragment, int, Predicate)} for an Activity
85      */
loadAccounts( final ActivityType activity, int id, final Predicate<AccountInfo> filter)86     public static <ActivityType extends Activity & AccountsListener> void loadAccounts(
87             final ActivityType activity, int id, final Predicate<AccountInfo> filter) {
88         loadAccounts(activity, activity.getLoaderManager(), id, filter, activity);
89     }
90 
loadAccounts(final Context context, LoaderManager loaderManager, int id, final Predicate<AccountInfo> filter, final AccountsListener listener)91     private static void loadAccounts(final Context context, LoaderManager loaderManager, int id,
92             final Predicate<AccountInfo> filter, final AccountsListener listener) {
93         loaderManager.initLoader(id, null,
94                 new LoaderManager.LoaderCallbacks<List<AccountInfo>>() {
95                     @Override
96                     public Loader<List<AccountInfo>> onCreateLoader(int id, Bundle args) {
97                         return new AccountsLoader(context, filter);
98                     }
99 
100                     @Override
101                     public void onLoadFinished(
102                             Loader<List<AccountInfo>> loader, List<AccountInfo> data) {
103                         listener.onAccountsLoaded(data);
104                     }
105 
106                     @Override
107                     public void onLoaderReset(Loader<List<AccountInfo>> loader) {
108                     }
109                 });
110     }
111 }
112